Portable type fastener driving tools can be classified as nail driving devices, pin driving devices (or tack driving devices) and staple driving devices and the like on the basis of the type of fastener which is being driven. On the other hand, they can be classified as devices using compressed air, the pressure of combustion, the brisance of gunpowder and electricity and the like on the basis of the driving source.
In any case, fastener driving tools are provided with rods which are used for driving and continuous driving is permitted by supplying the fasteners one by one to the front of the rod.
Fasteners which are used with fastener driving tools are made to connecting bodies which are connected by connecting material. The fastener connecting bodies are housed in a magazine and the fasteners are supplied one by one to the front of the rod by feeding them in one pitch increments inside the magazine.
There are two main types of connecting modes for a fastener group. In one mode, multiple fasteners are connected so that they are parallel to one another by using a connecting material which is made of a material which can alter its shape such as resinous tape and narrow wire (such as metal wiring) so that this fastener connecting body can be wound to a coiled shape (or rolled or formed like a spiral). This connecting mode is often used for nails.
In another connecting mode used for a fastener group, a fastener is retained by a connecting material which extends in a straight line and which is basically rigid. As a result, in this mode, the fastener connecting body cannot be wound in a coil shape. Resin and paper are often used for this type of connecting tool.
Further, the only type of fastener connecting body in which (a) the direction in which the fasteners are arranged and (b) the shaft line of each of the fasteners are mutually perpendicular to one another is the one which can be wound in a coil. There are two types of fastener connecting bodies which cannot be wound into coils: the type where (c) the direction in which the fastener group is arranged and (d) the shaft line of each of the fasteners are perpendicular to one another; and the type where (e) the direction in which the fastener group is arranged is tilted toward (f) the shaft line of each of the fasteners. The fact that there are two types in the latter category is brought about by a difference in the position of the magazine.
Next, we shall discuss the relation between the structure of the fastener connecting body and the driving tool by providing an example of the nail and the nail driving device.
A nail connecting body which has a rectilinear shape is loaded onto a magazine so that it extends in a long straight line. The nail connecting body which has a rectilinear shape is advantageous in that it has an overall rigid body structure and does not require a special motive power and can be fed reliably by using a simple feed mechanism which uses an extension spring or a compression spring.
However, since there are limits on the length of the magazine to maintain easy handle and operation for the nail driving device users, there are limits on the length of a single nail connecting body (limits on the number of nails which can be used to make up a single nail connecting body). Therefore, in operations which involve driving a large quantity of nails in a short period of time such as when buildings are built using the 2×4 method, it is disadvantageous in that the nail connecting body must be frequently replaced.
On the other hand, nail connecting bodies which can be wound in a coil shape are advantageous in that they are loaded onto a drum shaped magazine which is schematically round when seen in cross section and a large number of nails can be accommodated efficiently inside the magazine. In other words, a single nail connecting body can be consisted of a great many nails. For this reason, it is suitable for operation for construction in which large quantities of nails are used.
Be that as it may, the nail connecting bodies which are wound into a coil shape cannot be fed just by pressing (or pulling) on a spring and a feed mechanism which has a movable feed member must be set in place near the rod.
For a nail driving tool (a “coil nailer”) which uses a nail connecting body which has been wound into a coil shape, almost without exception an “air tool” which uses compressed air as the drive source is used. Specifically, a small piston used for feeding the nails is driven by compressed air, and the fastener connecting bodies are fed by using a lever which does elliptic movement links with the reciprocating motion of the piston.
However, air tools present problems in that they require an air compressor so that maneuverability is lacking on the work site. In addition, since an air hose bring resisting effect to the movement of the tool, there are problems in that a heavy burden in placed on the operator. It is unpleasant for an operator to carry out fastening operations while manipulating a hose at a work site which is cluttered with many members.
On the other hand, a “gas tool” which uses gas combustion pressure as the power source for the rod is advantageous in that it does not require special accessory devices and has outstanding maneuverability. As a result, fastening operations can be carried out anywhere and there is little physical burden placed on the operator as there is no hose. However, the prior art gas tool was inconvenient in that it could only be used with a rectilinear nail connecting body so that the nail connecting bodies had to be replaced frequently within a short period of time at a work site where many nail driving operations were being carried out.
Therefore, experiments have been carried out to use coil type nail connecting bodies on gas tools (in other words, experiments on developing a gas combustion type coil nailer). An example of this is disclosed in Patent Document 1 in which feeding of nails had been carried out using partial gas combustion pressure as a power source. Specifically, it discloses that on a gas tool (a) a nail feeding device which is equipped with a nail feeding piston like a coil type connecting nail air tool and part of the combustion gas is introduced to a cylinder in which a nail feeding piston is inserted.
[Patent Document 1] Publication of Unexamined Utility Model Application H5-72380